Hello, I’m just posting here due to conflicting responses below regarding what you need to have to complete the quest. The Rat King quest requires “other rats” The first groups were able to complete it because they were all doing the quest together. But because newer players would later on get the quest and may not have friends that hadn’t already completed it, Bungie made sure that as long as one other person had the Rat King [u][b]equipped[/b][/u] it would count. I have tried and tested this myself with myself having the quest, and my fireteam not having the quest and having the Rat King in their inventory, not equipped. I didn’t get the Rat King at the end of the nightfall with plenty of time remaining. So we ran it again with the Rat King equipped and only myself having the quest, and I was awarded the Rat King at the end. TL;DR: at least one of more of your fireteam must either be on the same step in the quest [b][u]OR[/u][/b] have the Rat King equipped.